1. Field of Disclosure
This disclosure generally relates to a seal used in an image forming apparatus such as a printer, a facsimile machine, and a copier, a cleaning device including the seal and an image forming unit including the cleaning device.
2. Discussion of the Background Art
An electrophotographic device includes at least a charge device that charges a photoreceptor, an exposure device that forms a latent image on the photoreceptor, a developing device that adheres to toner on the latent image, and a photoconductive cleaning device that removes an untransferred toner on the photoreceptor.
The photoconductive cleaning device includes a cleaning member 54, which is an elastic plate, whose edge 54a contacts a photoreceptor 51 to scrape an untransferred toner, as shown in FIGS. 7,8, and 9. FIG. 7 shows a transfer roller 61, a charge roller 53, a developing roller 73, and a supply roller 74. The cleaning member 54 is a simple structure and reduces a size and a cost of the photoconductive cleaning device.
A sheet member 56 is arranged at an upstream side in a rotating direction of the photoreceptor 51 with respect to a contact portion at the photoreceptor 51 and an edge of the cleaning member 54. The sheet member 56, which is an elastic material, prevents toner scraped by the cleaning member 54 from falling to a transfer material. Thus, the toner scraped by the cleaning member 54 is accumulated in a space which is at an opposite side of the photoreceptor 51 with respect to the sheet member 56.
A seal member 57 that is an elastic material contacts the cleaning member 54, the sheet member 56, and an edge portion of the photoreceptor 51 in a longitudinal direction of a rotation axis as shown in FIGS. 9 and 10. The seal member 57 prevents toner scraped by the cleaning member 54 and toner accumulated the space from adhering to the photoreceptor 51 again.
Generally, the cleaning member 54 is made of a rubber plate. The sheet member 56 is an elastic sheet. The seal member is made of a material that combines a sponge with felt.
However, a gap occurs between the cleaning member 54 and the seal member 57. When the gap occurs, toner scraped by the cleaning member 54 is adhered to the photoreceptor 51 or the transfer material through the gap.
Japanese Unexamined Patent Application No. 10-301458 discloses an image forming apparatus that reduce the gap. In this apparatus, each of a first seal member and a second seal member, arranged on both sides in a longitudinal direction of a cleaning blade, presses to contact the cleaning blade and each of a first sidewall and a second sidewall. In case where Ta1 is a compressive deformation amount of the first seal member which receives a counterforce from the first sidewall, Ta2 is a compressive deformation amount of the second seal member which receives a counterforce from the second sidewall, and Tc is a swinging stroke of the cleaning blade, Ta1 is greater than Tc and Ta2 is greater than Tc.